Look to FFTF for a completely successful fast reactor run in the U.S. that was unfortunately shut down for political reasons that, retrospectively, look like a terrible mistake.

One of the most interesting features of the FFTF was a sodium-to-air heat exchanger which is a key to fast reactors having superior economics.

That is, no nuclear reactor which uses a steam turbine is going to be economically competitive with fossil fuel fired gas turbine generators. Between the absolutely huge and massive steam turbine and absolutely huge and massive heat exchangers (look at how big the steam generators are in the PWR or the huge tube-in-shell heat exchanger used at Dounreay)

A closed cycle gas turbine will fit in the employee break room of the turbine house of a conventional LWR. It requires some kind of reactor that runs at a higher temperature than the LWR. I like fast reactors and molten salts but have a hard time being enthusiastic about HTGR and friends.

So much of the literature still looks like a stopped clock. People still compare nuclear to coal although coal has been economic for a long time for the same reason as the LWR... The cost of that huge steam turbine.

Problems with fast reactors I worry about are the fear of proliferation (not proliferation) constricting what you can use for fuel and (more so) the plutonium nanoparticle problem w/ MOX fabrication. Of course you don't need to use MOX or you'd think in 2022 you could use 100% remote handling and not have the problems that Karen Silkwood was worried about at the place where she worked.